Seropositivity for anti-Trypanosoma cruzi antibodies among blood donors of the "Hospital Universitário Regional do Norte do Paraná", Londrina, Brazil

The most frequent form of acquisition of Chagas' disease in endemic areas was the transmission through the feces of contaminated triatominae. However, special attention should be paid in urban areas to transmission by blood transfusion, justifying the compulsory screening of blood donors. Early investigations at blood banks in the town of Londrina, Brazil, demonstrated that the seroprevalence of anti-Trypanosoma cruzi antibodies among blood donors was approximately 7.0% in the fifties9,34. Further studies demonstrated pratically the same seroprevalence until the eighties4,32,41. In an attempt to obtain data about the real dimension of the seropositivity for anti-Trypasonoma cruzi antibodies in the region, the authors carried out a large-scale study on 45,774 serum samples from blood donors of the Hemocentro of Hospital Universitário Regional do Norte do Paraná (HURNP), Universidade Estadual de Londrina. The immunological tests were done at the Division of Clinical Immunology of HURNP from May 1990 to December 1994. The serum samples were studied by the indirect hemagglutination assay (IHA, using kits commercially obtained from EBRAM) and by indirect immunofluorescence (IFI, using kits from LIO SERUM) with anti-human IgG conjugate (LABORCLIN). The results demonstrated that 643 serum samples were positive in both assay corresponding to a seroprevalence of 1.4%, i.e., a significant decrease in anti-Trypanosoma cruzi antibodies in the region in comparison with the previously mentioned rates. Data correlating sex and age of seropositive blood donors are presented, as well as the possible factors that may have contributed to the results observed.

Download Full-text

The Cross Roads of Heritage

10.26686/wgtn.17148947.v1 ◽

2021 ◽

Author(s):

◽

Philippa Dalgety

Keyword(s):

New Zealand ◽

Urban Areas ◽

Large Scale ◽

Adaptive Reuse ◽

Built Form ◽

Depth Analysis ◽

Key Factor ◽

History Of ◽

Fit For Purpose ◽

The Town

<p>This research explores an approach for adaptive reuse to enhance livability and greater connection to place within provincial towns of New Zealand. There are existing buildings which are often left in disrepair or considered too expensive to refurbish or strengthen. They are often demolished with little consideration to the building’s significance, therefore adaptive reuse has become a missed opportunity in New Zealand. Many of our provincial cities have uninhabited large-scale buildings, which need upgrading due to being outdated and no longer fit for purpose. Seismic upgrading is a key factor in why these buildings are left uninhabited. One of the urban areas which this is prevalent is Whanganui. Whanganui has the opportunity to blend the old and the new built form to create a revitalized and timeless street appearance. The regeneration of Whanganui can be achieved through adaptive reuse to enhance the crafted beauty of the town through its architecture. The revitalization of Whanganui can give guidance to other provincial cities in New Zealand while enhancing the quality of life within the town. An in-depth analysis of the history of Whanganui, will allow for heritage significance to play a major role in the redesign. This design will be developed at three different scales to demonstrate how the built form can enhance connection to place and livability. These scales are at an urban, a built and a detailed scale. The main cross roads linking the city of Whanganui to its river is surrounded by character and historical buildings. It will be used as a key area illustrating Whanganui’s past to better inform the future.</p>

Download Full-text

First report of Chlamydia psittaci seroprevalence in black-headed gulls (Larus ridibundus) at Dianchi Lake, China

Open Life Sciences ◽

10.1515/biol-2018-0030 ◽

2018 ◽

Vol 13 (1) ◽

pp. 250-252

Author(s):

Hua Chang ◽

Jiangqiang Han ◽

Yan Yang ◽

Gang Duan ◽

Fengcai Zou ◽

...

Keyword(s):

Human Health ◽

Potential Risk ◽

Wild Bird ◽

Chlamydia Psittaci ◽

Dianchi Lake ◽

Serum Samples ◽

Present Survey ◽

Hemagglutination Assay ◽

Larus Ridibundus ◽

Indirect Hemagglutination

AbstractChlamydiosis is an important zoonosis which can transmit from birds to humans, and investigation first reported the seroprevalence of Chlamydia psittaci in black-headed gulls (Larus ridibundus) at the Dianchi Lake, China. A total of 1029 serum samples collected from black-headed gulls between 2012-2015 were analyzed. The gulls were randomly caught and blood collected at Dianchi Lake, China. All the samples were analyzed for the presence of antibodies to C. psittaci by indirect hemagglutination assay (IHA). In this survey, the total infection rate was 11.86% (122/1029). The results of the present survey documented the existence of relatively high C. psittaci seroprevalence in black-headed gulls, which have a potential risk to the wild bird health and human health. Comprehensive practical control approaches and measures should be executed.

Download Full-text

The Cross Roads of Heritage

10.26686/wgtn.17148947 ◽

2021 ◽

Author(s):

◽

Philippa Dalgety

Keyword(s):

New Zealand ◽

Urban Areas ◽

Large Scale ◽

Adaptive Reuse ◽

Built Form ◽

Depth Analysis ◽

Key Factor ◽

History Of ◽

Fit For Purpose ◽

The Town

Download Full-text

Seroprevalence, waning, and correlates of anti-SARS-CoV-2 IgG antibodies in Tyrol, Austria: Large-scale study of 35,193 blood donors conducted between June 2020 and September 2021

10.1101/2021.12.27.21268456 ◽

2021 ◽

Author(s):

Anita Siller ◽

Lisa Seekircher ◽

Gregor A Wachter ◽

Manfred Astl ◽

Lena Tschiderer ◽

...

Keyword(s):

Large Scale ◽

Blood Donors ◽

Participation Rate ◽

Federal State ◽

Igg Antibodies ◽

Serum Samples ◽

Serological Tests ◽

Nucleocapsid Proteins ◽

Antibody Levels ◽

Prior Infection

Background: There is uncertainty about the seroprevalence of anti-SARS-CoV-2 antibodies in the general population of Austria, and about the extent to which antibodies elicited by vaccination or infection wane over time. Aim: To estimate seroprevalence, waning, and correlates of anti-SARS-CoV-2 IgG antibodies in the Federal State of Tyrol, Austria. Methods: We conducted a seroepidemiological study between June 2020 and September 2021, enrolling blood donors aged 18-70 years across Tyrol, Austria (participation rate 84.0%). We analysed serum samples for antibodies against spike or nucleocapsid proteins of SARS-CoV-2 with Abbott SARS-CoV-2 IgG assays. Results: We performed 47,363 serological tests among 35,193 individuals (median age 43.1 years [IQR: 29.3-53.7], 45.3% women, 10.0% with prior SARS-CoV-2 infection). Seroprevalence increased from 3.4% (95% CI: 2.8-4.2%) in June 2020 to 82.7% (95% CI: 81.4-83.8%) in September 2021, largely due to vaccination. Anti-spike IgG seroprevalence was 99.6% (99.4-99.7%) among fully vaccinated individuals, 90.4% (88.8-91.7%) among unvaccinated with prior infection, and 11.5% (10.8-12.3%) among unvaccinated without known prior infection. Anti-spike IgG levels were reduced by 44.0% (34.9-51.7%) at 5-6 months compared to 0-3 months after infection. In fully vaccinated individuals, they decreased by 31.7% (29.4-33.9%) per month. In multivariable adjusted analyses, both seropositivity among unvaccinated and antibody levels among fully vaccinated individuals were higher at young age (<25 years), higher with a known prior infection, and lower in current smokers. Conclusion: Seroprevalence in Tyrol increased to 82.7% in September 2021, with the bulk of seropositivity stemming from vaccination. Antibody levels substantially and gradually declined after vaccination or infection.

Download Full-text

Seroprevalence for hepatitis E virus (HEV) infection among volunteer blood donors of the Regional Blood Bank of Londrina, State of Paraná , Brazil

Revista do Instituto de Medicina Tropical de São Paulo ◽

10.1590/s0036-46652006000200006 ◽

2006 ◽

Vol 48 (2) ◽

pp. 87-92 ◽

Cited By ~ 30

Author(s):

André Luiz Bortoliero ◽

Ana Maria Bonametti ◽

Helena Kaminami Morimoto ◽

Tiemi Matsuo ◽

Edna Maria Vissoci Reiche

Keyword(s):

Urban Areas ◽

Hepatitis E Virus ◽

Blood Donors ◽

Hepatitis A Virus ◽

Hepatitis E ◽

Developed Countries ◽

Blood Bank ◽

Igg Antibodies ◽

Serum Samples ◽

Sociodemographic Variables

A cross-sectional study was carried out among 996 volunteer blood donors enrolled from May 1999 to December 1999 to determine the seroprevalence of hepatitis E virus (HEV) infection among volunteer blood donors of the Regional Blood Bank of Londrina, State of Paraná, Brazil, and to evaluate whether the rate of seroprevalence of IgG anti-HEV antibodies is associated with sociodemographic variables and with seropositivity for hepatitis A virus (HAV) infection. All participants answered the questionnaire regarding the sociodemographic characterisitcs. Serum samples were tested for IgG antibodies to HEV (anti-HEV) by an enzyme linked immunoassay (ELISA). All serum samples positive for anti-HEV IgG and 237 serum samples negative for anti-HEV were also assayed for IgG anti-HAV antibodies by ELISA. Anti-HEV IgG was confirmed in 23/996 samples, resulting in a seroprevalence of 2.3% for HEV infection, similar to previous results obtained in developed countries. No significant association was found between the presence of anti-HEV IgG antibodies and the sociodemographic variables including gender, age, educational level, rural or urban areas, source of water, and sewer system (p > 0.05). Also, no association with seropositivity for anti-HAV IgG antibodies was observed (p > 0.05). Although this study revealed a low seroprevalence of HEV infection in the population evaluated, the results showed that this virus is circulating among the population from Londrina, South Brazil, and point out the need of further studies to define the clinical and epidemiological importance of HEV infection and to identify additional risk factors involved in the epidemiology and pathogenesis of this infection in this population.

Download Full-text

Epidemiological and Serological Study of Leishmaniasis in Najran Region, Saudi Arabia

Journal of Biology and Life Science ◽

10.5296/jbls.v8i1.10793 ◽

2017 ◽

Vol 8 (1) ◽

pp. 59

Author(s):

Mokhtar I. Khalil ◽

Mosa M. Bahnass ◽

M. I. M Abdallah

Keyword(s):

Saudi Arabia ◽

Prevalence Rate ◽

Domestic Animals ◽

Serological Study ◽

Serum Samples ◽

Hemagglutination Assay ◽

Disease Epidemiology ◽

Indirect Hemagglutination ◽

Human Leishmaniasis ◽

Animal Reservoirs

Leishmaniasis is a public health and veterinary hazard. Screening of serum samples of 384 human and 387 domestic animals were carried out by indirect hemagglutination assay (IHAT) to detect antibodies against L. donovani and to see the involvement of animal reservoirs in Najran region, Saudi Arabia. The overall prevalence of human Leishmaniasis infection in Najran area, Saudi Arabia was 8.3%. The prevalence rate of human Leishmaniasis was significantly higher in summer (21.9 %) and spring (8.3%) than in winter and autumn. In addition, the prevalence rate of human Leishmaniasis was significantly higher in old age (17.6%) and young period (7.3%). Out of 53 females and 331 males, 3 (5.7%) females and 29 (8.8%) males were found to be infected with human Leishmaniasis, respectively. The highest titer in human was 1/256 with percentage of 43.8%. Antibody against L. donovani in domestic animals was detected and the overall proportion of occurrence was 1.6%. The prevalence rate of Leishmaniasis infection was significantly higher in goats than in sheep, camel and horses. The highest titer (1/512) was in goats. The study was thrown light on infected African and Asian workers as source of Leishmaniasis infection. Also, this study suggests the possibility of varied species of domestic animals to harbor the parasite and hence play a central role in the transmission. Consequently, this may hurdle our clarification of disease epidemiology.

Download Full-text

Immunoassay with recombinant Trypanosoma cruzi antigens potentially useful for screening donated blood and diagnosing Chagas disease

Clinical Chemistry ◽

10.1093/clinchem/40.10.1893 ◽

1994 ◽

Vol 40 (10) ◽

pp. 1893-1897 ◽

Cited By ~ 25

Author(s):

A C Pastini ◽

S R Iglesias ◽

V C Carricarte ◽

M E Guerin ◽

D O Sánchez ◽

...

Keyword(s):

Trypanosoma Cruzi ◽

Test Procedure ◽

Horizontal Line ◽

Nitrocellulose Membrane ◽

Human Igg ◽

Recombinant Antigens ◽

Test Strips ◽

Blood Banks ◽

Indirect Hemagglutination ◽

Donated Blood

Abstract A new enzyme immunoassay (EIA), the Dia Kit Bio-Chagas assay (Gador S.A.), is potentially useful for detecting antibodies to Trypanosoma cruzi in the diagnosis of infected individuals and the screening of blood in blood banks. The EIA is carried out on test strips of plastic backing covered with a nitrocellulose membrane to which a mixture of recombinant T. cruzi antigens 1, 2, shed acute-phase antigen, 13, and 30 has been applied as a horizontal line. A horizontal line of human IgG is included to monitor the test procedure. The test strips exhibited homogeneity in the adsorption of the mixture of recombinant antigens (CV = 6.0%) and the human IgG (CV = 8.6%). The EIA results obtained with sera positive by xenodiagnosis showed 100% agreement between both types of tests; tested against sera with positive and negative matched results of indirect hemagglutination, immunofluorescence, and ELISA, the EIA results agreed for 99.1% (347 of 350) and 99.6% (299 of 300) of the samples, respectively.

Download Full-text

Comparison of Dot ELISA Using GroEL Recombinant Protein as an Antigen and an Indirect Hemagglutination Assay for Serodiagnosis of Melioidosis

The Open Microbiology Journal ◽

10.2174/1874285802115010036 ◽

2021 ◽

Vol 15 (1) ◽

pp. 36-42

Author(s):

Kanyanan Kritsiriwuthinan ◽

Sumet Wajanarogana ◽

Kantima Choosang ◽

Thitima Pimklang

Keyword(s):

Recombinant Protein ◽

Cost Effective ◽

Culture Method ◽

Serum Samples ◽

Hemagglutination Assay ◽

Indirect Hemagglutination ◽

Cost Effective Technique ◽

Specialized Equipment ◽

Dot Elisa ◽

Sensitivity Specificity

Background: Melioidosis is a disease caused by the Burkholderia pseudomallei bacterium. The mortality rate of infected patients is quite high because the symptoms are similar to those of various diseases, making it difficult to diagnose clinically and preventing the immediate treatment with effective antibiotics that is required for the management of acute infections. To provide appropriate treatment, accurate and rapid diagnosis is required. Objective: The aims of this study were to develop Dot ELISA using purified GroEL B. pseudomallei recombinant protein as an antigen and to compare the newly developed assay with an indirect hemagglutination assay (IHA) for the diagnosis of melioidosis. Methods: The GroEL recombinant protein was purified by immobilized metal affinity chromatography before being used as an antigen. The optimal conditions of the Dot ELISA were determined and used for subsequent experiments. A total of 291 serum samples were evaluated by the established Dot ELISA and IHA, using the bacterial culture method as the gold standard of melioidosis diagnosis. Results: The results from Dot ELISA and IHA revealed sensitivity, specificity, and accuracy of 85.7% (Dot ELISA)/64.3% (IHA), 94.4%/85.5%, and 93.1%/82.5%, respectively. Conclusion: These results indicate that the Dot ELISA developed is an efficient, simple, rapid and cost-effective technique for the early diagnosis of melioidosis and can be used in a local laboratory without specialized equipment.

Download Full-text

Development of Rapid Enzyme-Linked Immunosorbent Assays for Detection of Antibodies to Burkholderia pseudomallei

Journal of Clinical Microbiology ◽

10.1128/jcm.02856-15 ◽

2016 ◽

Vol 54 (5) ◽

pp. 1259-1268 ◽

Cited By ~ 32

Author(s):

Vichaya Suttisunhakul ◽

Vanaporn Wuthiekanun ◽

Paul J. Brett ◽

Srisin Khusmith ◽

Nicholas P. J. Day ◽

...

Keyword(s):

Burkholderia Pseudomallei ◽

Capsular Polysaccharide ◽

The United States ◽

Serum Samples ◽

Hemagglutination Assay ◽

Content Type ◽

Healthy Donors ◽

Indirect Hemagglutination ◽

Polysaccharide Antigens ◽

Immunosorbent Assays

Burkholderia pseudomallei, the causative agent of melioidosis, is an environmental bacillus found in northeast Thailand. The mortality rate of melioidosis is ∼40%. An indirect hemagglutination assay (IHA) is used as a reference serodiagnostic test; however, it has low specificity in areas where the background seropositivity of healthy people is high. To improve assay specificity and reduce the time for diagnosis, four rapid enzyme-linked immunosorbent assays (ELISAs) were developed using two purified polysaccharide antigens (O-polysaccharide [OPS] and 6-deoxyheptan capsular polysaccharide [CPS]) and two crude antigens (whole-cell [WC] antigen and culture filtrate [CF] antigen) ofB. pseudomallei. The ELISAs were evaluated using serum samples from 141 culture-confirmed melioidosis patients from Thailand along with 188 healthy donors from Thailand and 90 healthy donors from the United States as controls. The areas under receiver operator characteristic curves (AUROCC) using Thai controls were high for the OPS-ELISA (0.91), CF-ELISA (0.91), and WC-ELISA (0.90), while those of CPS-ELISA (0.84) and IHA (0.72) were lower. AUROCC values using U.S. controls were comparable to those of the Thai controls for all ELISAs except IHA (0.93). Using a cutoff optical density (OD) of 0.87, the OPS-ELISA had a sensitivity of 71.6% and a specificity of 95.7% for Thai controls; for U.S. controls, specificity was 96.7%. An additional 120 serum samples from tuberculosis, scrub typhus, or leptospirosis patients were evaluated in all ELISAs and resulted in comparable or higher specificities than using Thai healthy donors. Our findings suggest that antigen-specific ELISAs, particularly the OPS-ELISA, may be useful for serodiagnosis of melioidosis in areas where it is endemic and nonendemic.

Download Full-text

Serologic Testing for Trypanosoma cruzi: Comparison of Radioimmunoprecipitation Assay with Commercially Available Indirect Immunofluorescence Assay, Indirect Hemagglutination Assay, and Enzyme-Linked Immunosorbent Assay Kits

Journal of Clinical Microbiology ◽

10.1128/jcm.38.2.639-642.2000 ◽

2000 ◽

Vol 38 (2) ◽

pp. 639-642 ◽

Cited By ~ 59

Author(s):

David A. Leiby ◽

Silvano Wendel ◽

Deise T. Takaoka ◽

Roberta M. Fachini ◽

Lea C. Oliveira ◽

...

Keyword(s):

Trypanosoma Cruzi ◽

Indirect Immunofluorescence ◽

Blood Donors ◽

The United States ◽

Test Methods ◽

Immunofluorescence Assay ◽

Indirect Immunofluorescence Assay ◽

Confirmatory Test ◽

Indirect Hemagglutination ◽

Radioimmunoprecipitation Assay

The radioimmunoprecipitation assay (RIPA) has been used as a confirmatory test in several ongoing and published studies ofTrypanosoma cruzi in blood donors in the United States. Despite its use as a confirmatory test, few studies are available comparing RIPA to commercially available serologic test methods. Thus, we compared RIPA with two indirect hemagglutination assays (Biolab Diagnostica SA, São Paulo, Brazil; Hemagen Diagnostics, Inc., Waltham, Mass.) and four different enzyme-linked immunosorbent assays (Abbott Laboratories, Abbott Park, Ill.; Embrabio, São Paulo, Brazil; Organon Teknika, São Paulo, Brazil; and Gull Laboratories, Salt Lake City, Utah) using a panel of 220 serum specimens from Brazilian blood donors with a range of T. cruzi antibody titers as determined by indirect immunofluorescence assay (IFA). A titer of 1:20 was used as the baseline for seropositivity. All IFA-negative serum specimens (n = 19) were nonreactive on all tests. At a titer of 1:20 (n = 9), reactivity rates varied considerably among the tests, with only the RIPA and the Organon and Gull assays identifying reactive specimens. For specimens at a 1:40 titer (n = 35), most assays identified at least 32 of 35 (91%) specimens as reactive, but the Biolab assay only identified 24 (69%). At higher titers (1:80, n = 56; 1:160,n = 101) the assays were comparable, with the exception of the Biolab assay, demonstrating rates of agreement with IFA of ≥98%. Overall, when compared with several other test formats, RIPA demonstrated equivalent or superior rates of agreement with IFA-positive specimens across all titers examined. In particular, at titers of >1:40, the RIPA compared favorably with other test methods currently in use, supporting its application as a confirmatory test, particularly in a research setting.

Download Full-text